Sequencing of DNA and proteins has heralded a biotechnology revolution. Our ability to determine the nucleic acid or polypeptide structure with a specific biological function has enabled us to probe biological phenomenon in a mechanistic, rigorous manner and facilitated the development of novel therapeutics. However, this approach has yet to be achieved with the third major class of biopolymer, viz., polysaccharide. Complex polysaccharides of the glycosaminoglycan (GAG) family are important modulators of numerous biological processes, from development to neovascularization to maintenance of the nervous system. However, expect for a few cases, it is still unknown how GAG structures impinge on function. Only with this knowledge will it be possible to utilize the information inherent in GAGs, either scientifically or therapeutically. To this end, the principal investigator has recently developed a powerful sequencing approach for a subset of GAGs (heparan sulfate-like glycosaminoglycans or HLGAGs). One of the primary experimental constraints used in this sequencing approach is the heparinases, a group of polysaccharide lyases from Flavobacterium heparinum that the principal investigator has cloned and characterized. In this grant proposal, he proposes to extend the repertoire of tools for use in the sequencing approach and to probe further the biological functions of GAGs. He proposes to do this in two ways: (1) Clone and biochemically characterize other HLGAG-degrading enzymes from F. heparinum, and (2 establish a complementary sequencing approach for chondroitin/dermatan sulfate GAGs using the chondroitinases from F. heparinum. In this manner, the principal investigator hopes to broaden the knowledge of complex polysaccharides and learn how structure translates to function.